Reversing apparatus for furnaces



March 4;, 1947. o. REINER REVERSING APPARATUS FOR FURNACES Filed March 9, 1940 2 Sheets-Sheet l kwm wg WE v twnkEG Kw Attorney March 4, 1947.

I O. REINER REVERSING APPARATUS FOR FURNACES Filed March 9, 1940 2 Sheets-$heet 2 Inventor 07m RE/NER AM filb I A 353,0 2G 1 Attorney Patented Mar. 4, 1947 REVERSING APPARATUS FOR FURNACES Otto Reiner, Rheinhausen-Nrh.-Hochemmerich, Germany; vested in the Attorney General of the United States Application March 9, 1940, Serial No. 323,160 In Germany November 15, 1937 2 Claims.

This invention relates to apparatus for reversing the heating gas current, the-air current and the Waste-gas current, also for supplying the air in connection with industrial furnace plants operating with alternating gas and air currents.

It is known to shut-off the heating gas current prior to the reversal of the furnace by means of valves in order to prevent chimney losses during the reversal. This manner of operating causes an increase of the pressure in the gas conduit so that other furnaces connected to the same gas conduit receive too large amounts of the gas, of which a part escapes in an unburnt state through the chimney because of the lack of air. Besides, any combustion of gas in the furnace ceases when the heating gas currentis shut-off, in consequence whereof no smoke gases for producing a draught in the chimney are generated, whereby the furnace is sucked empty during this period and cold air finds access into the furnace and the heating chambers. The consumption of heat units for compensating such a drop of temperature is larger than the consumption due to the loss of heating gas, in consequence whereof the losses of chimney gas cannot be wholly pre-' vented by a prior shutting-off of the heating gas current.

It is furthermore known to reverse, while the furnace is being reversed, first the heating gas current and thereafter the air current in order to attain separate sucking-off of the current of the return gas and the current of the return air through the chimney so that no explosions in the chimney flue can occur. This procedure suffers, however, from the drawback that the combustion of the gas in the furnace side having been heated does not uniformly cease and that after the re,- versal of the furnace the gas and the air do not uniformly escape whereby a substantial increase of the fusing time and an increased gas consumption is entailed.

An object of the present invention is to ob viate the above-mentioned disadvantages of the former reversing methods and devices by apparatus in which the gas supplied to the furnace is continually deflected without any loss of gas by the chimney conduit and without. any throttling or shutting-off. A characteristic feature of the invention is that while carrying out the reversing procedure first the abstraction of the waste-gases from the gas chamber of that furnace side which up to then had been in connection with th discharge chimney through said chamber, as well as through the appertaining air chamber, is interrupted and thereafter the wastegases from said furnace side aresucked away solely through the air chamber until the reversing has been finished. This sucking takes place in an increased degree relatively to the'preceding sucking and thereafter, the supply of air also 2 to the furnace side having been heated is interrupted so that the air supply to both furnace sides is shut-off in the common air conduit. Simultaneously therewith the reversal of the sup ply of the heating gas to, and the withdrawal of the waste-gas from, the two furnace sides, as

well as the supply of air to the furnace side now to be heated, are effected with such a small delay relatively to the supply of the heating gas to this furnace side that the current of air and the current of waste-gas meet one another at the burning place of this furnace side which is now to be heated so that at the moment in which the reversal has been finished the correct heating of the furnace side in question takes place at once.

Thus the supply of gas to the furnace takes place uninterruptedly so that after the reversal of the gas current the smoke gases present in the regenerative chambers of the furnace side having been heated up to then are pressed into the furnace during'the interruption and can be sucked away through the chimney, so that at the instant at which the heating gases enter into the furnace the supply of the air into the furnace takes place.

Another advantage provided by the present invention is that owing to the continuous supply of the gas smoke gases effecting the sucking action in the chimney are likewise continuously available for this purpose so that the chimney is never able to suck cold air (false air) into the furnace and into the heating chambers, whereby the gas and the air after the furnace reversalat the burner take place simultaneously so that neither an oxidising, nor a reducing combustion of the heating gases occurs, nor is anexcess of gas or of air supplied to the furnace.

Finally, also the advantage exists that the return air current coming from the air generator chambers is sucked off through the chimney separately from the return gas current coming from the gas generatorchambers, the gas and the air being simultaneously reversed, whereby any possibility of the occurrence of an explosion is completely prevented.

The invention will be more thoroughly understood upon reference tothe annexed drawings and the following description wherein an exemplary embodiment of the invention is disclosed.

In the drawings Figure 1 is a top plan View showing apparatus according to the invention.

Figures 2, 3 and 4 are fragmentary Vertical sectional elevational views taken substantially on chamber G'r, as

3 V the planes indicated by the lines II II, III-III, and IVIV, respectively, in Figure 1.

In this constructionalform of the device'thej shutting-off members are formed by disk valves combined with a water seal, but I wish it to be understood that instead of disk valves also valves of another design, as well as other suitable shutthe scope of the invention. In the drawings the right-hand side of the furnace plant with its reversing device, or reversing members respectively, includes the gas cham- 4 I the change-over flap 4 is suddenly turned over' by means of a motor provided for the purpose, and simultaneously therewith also the'throttle' flap 1 in the air pipe is suddenly turned over by an electro-motor or any other known electromagnetic implement into "its closing position so ting-off members, may be used without affecting that from this moment the air supplyto the air chamber Lg is interrupted so that neither of the two furnace sides receives air. From the moment of the reversal of the shutting-off devices the heating gas is supplied on the right-hand side of the furnace into the gas chamber Gr but, no

ber GT and the air chamber Lr, connected to the conduit K which is connected to the chimney, whereas the gas chamber (3g of the left-hand furnace side is supplied with heating gas and the air chamber Lg of said side with compressedair.

I (Fig. 3) denotes the common gas supply conduit'below which is arranged a changeeover flap 4 located between the branch pipes 3g and 31' which terminate at the heating gas reversing valves 29 and 22, the said flap 4 shutting-off in the position shown in Fig, 3 the communication between the conduit 5 and the pipe 3?.- The valve 21' is closed, whereas the valve 29 is open. "In,

the conduit iii leading from the gas chamber G1 to the chimney is arranged a disk valve 5r and in the conduit H leading from the gaschamber Gwg to the chimney is arranged avalve by. In the position of these valves as shown the valve 5r is open and the valve 59 closed. In the common air supply pipe 6 which leads to the air chambers LT and Lg is arranged a throttle flap! at the place shown in Figs. 1 and .4. When this flap is turned from the position shown in Figs. 1 and4, in which it is open, into the other position it closes and interrupts the supply of air to the air chambers of both'sides of the furnace.

In the pipe 64 leading'from the common air supply. pipe 6 to the air chamber L1 is arranged a valve 31", and in the pipe 15 leading from the pipe 5 to the air chamber Lg is arranged a valve to.

Furthermore, a valve 91' is arranged in the pipe 29 connecting the air chamber L1" with the chimney, and a valve 9g is arranged in the pipe 2! connecting the air chamber Ly with the chimney.

In the position of theseveral members mentioned the valve 31" is closed and the valve S g open, whereas the valve eriis open andthe valve 9g closed. There is, therefore, in these positions of these valves the left-hand side of the furnace heated, whereas the right-hand side of the same i communicates with the chimney through the gas well as through the air cham;

ber Lr.

If new the supply of gas and of air to the furnace be reversed, first an electromotor (not shown) is started in known manner and rotated air is suppliedto the air chamber Lg of the lefthand side of the furnace whereby no unburnt been .reversedjand the shutting-01f device .1 has been closed, the electromotors pertaining to the valves '81 and to are started whereby the valve 81 will be opened and the valve er will be closed and also the valve to will be closedand the valve 9g opened. Thus, all valves engaged in the air supply are reversedat the same time. 1

When this has been effected the shutting-off device I located in the air blast conduit is, again opened and'eith'er simultaneously therewith or a moment thereafter the position of the valves 2g and 5g is reversed wherewithsthe reversing procedure will be completed.

From the moment of the re-opening of the shutting-off device I air flows to the right-hand furnaceside into the air chamber Lr,.and the reversal of the air -supply takes place relatively to the reversal of the gas supply by the opening of the 'valve 21 so that when theheating gas arrives at the burning place of the right-hand furnace side also the air arrives atvsa'id place so that now t'he heating of this side of the fur na'ce commences without solely gas or solely air being pressed into the right-handv side of the furnace. This is rendered possible bythe fact that the conduits through which the gas passes to the furnace .are' longer than the conduits through which'the air passes frointhe'reversing I device to the furnace, so that, for instance,- '25 seconds'will elapse between the time at which withsuch a low' speed that the valve 51* is slowly I lowered and at the same time the valve 2r is opened. The valves 57' and 21' are connected with one another by a rope, and as the valve 5r is heavier than the valve 27' the valve 51 will lift the between the gas chamber Gr and the chimney valve 21' when it is lowered. Owingto the slow movement of the. valve 51 the communication will-be slowly interrupted and when the valve 51' has been completely closed the waste gases will be sucked off from the right-hand side of the furnace through the air chamber Lr, this sucking off of the gases from the right-hand side of the furnace through the air chamber L7 taking place more strongly than the gases had been sucked off prior thereto through the air chamber hr;

After the valves 21' and 51' have been reversed,

the flap '4 is turned over'and the time g-as arrives at the place of burning, whereas only 15 seconds will elapse from thejtime :at which the shutting-off device Iis again opened, so that 1-0 seconds are available for the reversal of the air supply. A When-the'above described reversing procedure has been finished, the right-hand side of- 'the g furnace is heated, whereas the left-'hand s'ide of the same is connected with the chimney 'th-IOUg h the air chamber Lo and the "opened valve 99,

aswell as through the gas chambe'r Go and the opened valve 5. 7. The provision of a separate's'huttin-g off device"? for the temporary interruption of the supply of air, instead ofeffect'ing this interruption by stopping the fan producing the compressedair, provides improvements-in the reversing device, as stopping and starting a ianreqnires 'by far too-much time. i V

A" reversing device suited for carrying out" the of air is he s interrupted by the shutting-oil device whereafter the further reversing procedure takes place practically in the manner above described, the only exception being that, as the valve 2g is being closed wl e the valve 21 is being opened, only the valv need be ,ed at the instant the reversal of the air is b finished.

It is also possible to do without the separate valve 7, but the control device must then be so designed that after the gas valve 22 has been opened, first the air valve 9g is closed, and only then the other valves are reversed, so that, with this reversing procedure, the supply of air to the two furnace sides is likewise stopped for a certain period of time. The procedure entails the necessity that the reversal of the valve 94;! be done ahead of the reversal of the valves 91", 9c and 81".

After a push-button switch (not shown) has been actuated, first the valve 51' is closed, whereby the waste-gas current flowing from the gas chamber Gr to the chimney K is interrupted. The entire amount of the waste-gas is then sucked away through the air chamber L1. Now the following valves are moved simultaneously, the valve 27* is opened and the valves 29 and 8g are closed, whereby the gas current is continually deflected from the left-hand side of the furnace to the right-hand side thereof. As the valves 29 and 8g have been closed at the same time, the combustion of the gas in the left-hand side of the furnace ceases proportionally, whereby neither an oxidising combustion, nor a reducing combustion of the heating gas can arise. The supply of air to the furnace is interrupted in that the valve 8g is closed. Now the valves 91" and 99 are likewise moved at the same time and with equal transverse sections, the valve 91" being closed and the valve 99 opened, whereby the waste-gas current is deflected from the air chamber Lr to the air chamber L9. The entire amount of the waste-gas is then sucked away by the chimney through the air chamber Lg and simultaneously therewith the air in the air chamber Lg is sucked away together with the waste-gas flowing to the chimney, whereby no return air comes in contact with the return gas from the gas chamber Gy and, therefore, no ignition in the chimney flue can occur. Thereafter the valve 81 is opened by suitable means provided for the purpose and the current of air is thereby released with a certain delay so that the furnace is fed with gas and with air at the same time. Thereafter the valve 59 is opened whereby the current of gas will be liberated as soon as the return air still present in the air chamber Lg has been completely sucked away by and through the chimney, and simultaneously therewith the return gas still present in the gas chamber Gg will be sucked away. All this having been accomplished, the

furnace is reversed and operates with continual supply of gas and continual withdrawal of waste gas in known manner.

I claim:

1. In apparatus for reversing the how of heating gas and air in an alternately heated regenerative furnace having air chambers and gas chambers; a gas supply conduit having branches, a valve for directing gas from said supply conduit into any of said branches, a chimney conduit connected between each furnace gas chamber and related ones of said branches, other valves for closing off the said'branches individually, valves for individually closing the chimney conduits at points between the chimney and the branches of the gas conduit, an air supply conduit, a further valve for closing said air supply conduit, said air supply conduit having branches connected with the furnace air chambers, branches connecting said chimney conduit with the air supply conduit branches, further valves for individually closing the air supply conduit branches, and other valves arranged for individually closing the chimney conduit branches at points between the connections of the chimney conduit branches with the chimney conduit and with said air supply conduit branches.

2. In apparatus for reversing the flow of heating gas and air in an alternately heated regenerative furnace having two air chambers and two gas chambers; a gas supply conduit having two branches, a valve for directing gas from said supply conduit into either of said branches, a chimney conduit connected between each furnace gas chamber and the related branch, other valves for closing off said branches individually, valves for individually closing the chimney conduits at points between the chimney and the branches of the gas conduit, an air supply conduit, a further valve for closing said air supply conduit, said air supply conduit having two branches connected with the furnace chambers, two branches connecting said chimney conduit with the air supply conduit branches, further valves for individually closing the air supply conduit branches, and other valves arranged. for individually closing the chimney conduit branches at points between the connections of the chimney-conduit branches with the chimney conduit and with said air supply conduit branches.

OTTO REINER.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS French July 24, 1939 

